/*
* Finds and removes all cut edges from the graph.
* @return a list of the LineString forming the removed cut edges
*/
vector<const LineString*> *
PolygonizeGraph::deleteCutEdges()
{
computeNextCWEdges();
// label the current set of edgerings
delete findLabeledEdgeRings(dirEdges);
/*
* Cut Edges are edges where both dirEdges have the same label.
* Delete them, and record them
*/
vector<const LineString*> *cutLines=new vector<const LineString*>();
for(int i=0;i<(int)dirEdges->size();i++) {
PolygonizeDirectedEdge *de=(PolygonizeDirectedEdge*)(*dirEdges)[i];
if (de->isMarked()) continue;
PolygonizeDirectedEdge *sym=(PolygonizeDirectedEdge*) de->getSym();
if (de->getLabel()==sym->getLabel()) {
de->setMarked(true);
sym->setMarked(true);
// save the line as a cut edge
PolygonizeEdge *e=(PolygonizeEdge*) de->getEdge();
cutLines->push_back(e->getLine());
}
}
return cutLines;
}
/**
* Computes the EdgeRings formed by the edges in this graph.
* @return a list of the EdgeRing found by the polygonization process.
*/
vector<polygonizeEdgeRing*>*
PolygonizeGraph::getEdgeRings()
{
// maybe could optimize this, since most of these pointers should
// be set correctly already
// by deleteCutEdges()
computeNextCWEdges();
// clear labels of all edges in graph
label(dirEdges,-1);
vector<PolygonizeDirectedEdge*> *maximalRings=findLabeledEdgeRings(dirEdges);
convertMaximalToMinimalEdgeRings(maximalRings);
delete maximalRings;
// find all edgerings
vector<polygonizeEdgeRing*> *edgeRingList=new vector<polygonizeEdgeRing*>();
for(int i=0;i<(int)dirEdges->size();i++) {
PolygonizeDirectedEdge *de=(PolygonizeDirectedEdge*)(*dirEdges)[i];
if (de->isMarked()) continue;
if (de->isInRing()) continue;
polygonizeEdgeRing *er=findEdgeRing(de);
edgeRingList->push_back(er);
}
return edgeRingList;
}
/* public */
void
PolygonizeGraph::getEdgeRings(std::vector<EdgeRing*>& edgeRingList)
{
// maybe could optimize this, since most of these pointers should
// be set correctly already
// by deleteCutEdges()
computeNextCWEdges();
// clear labels of all edges in graph
label(dirEdges, -1);
std::vector<PolygonizeDirectedEdge*> maximalRings;
findLabeledEdgeRings(dirEdges, maximalRings);
convertMaximalToMinimalEdgeRings(maximalRings);
maximalRings.clear(); // not needed anymore
// find all edgerings
for(unsigned int i=0; i<dirEdges.size(); ++i)
{
PolygonizeDirectedEdge *de=(PolygonizeDirectedEdge*)dirEdges[i];
if (de->isMarked()) continue;
if (de->isInRing()) continue;
EdgeRing *er=findEdgeRing(de);
edgeRingList.push_back(er);
}
}
void
PolygonizeGraph::computeNextCWEdges()
{
vector<planarNode*> *pns=getNodes();
// set the next pointers for the edges around each node
for(int i=0;i<(int)pns->size();i++) {
planarNode *node=(*pns)[i];
computeNextCWEdges(node);
}
delete pns;
}
void
PolygonizeGraph::computeNextCWEdges()
{
typedef std::vector<Node*> Nodes;
Nodes pns; getNodes(pns);
// set the next pointers for the edges around each node
for(Nodes::size_type i=0, in=pns.size(); i<in; ++i) {
Node *node=pns[i];
computeNextCWEdges(node);
}
}
/* public */
void
PolygonizeGraph::deleteCutEdges(std::vector<const LineString*> &cutLines)
{
computeNextCWEdges();
typedef std::vector<PolygonizeDirectedEdge*> DirEdges;
// label the current set of edgerings
DirEdges junk;
findLabeledEdgeRings(dirEdges, junk);
junk.clear(); // not needed anymore
/*
* Cut Edges are edges where both dirEdges have the same label.
* Delete them, and record them
*/
for (DirEdges::size_type i=0, in=dirEdges.size(); i<in; ++i)
{
DirectedEdge *de_ = dirEdges[i];
#ifdef GEOS_CAST_PARANOIA
assert(dynamic_cast<PolygonizeDirectedEdge*>(de_));
#endif
PolygonizeDirectedEdge *de =
static_cast<PolygonizeDirectedEdge*>(de_);
if (de->isMarked()) continue;
DirectedEdge *sym_ = de->getSym();
#ifdef GEOS_CAST_PARANOIA
assert(dynamic_cast<PolygonizeDirectedEdge*>(sym_));
#endif
PolygonizeDirectedEdge *sym =
static_cast<PolygonizeDirectedEdge*>(sym_);
if (de->getLabel()==sym->getLabel())
{
de->setMarked(true);
sym->setMarked(true);
// save the line as a cut edge
Edge *e_ = de->getEdge();
#ifdef GEOS_CAST_PARANOIA
assert(dynamic_cast<PolygonizeEdge*>(e_));
#endif
PolygonizeEdge *e = static_cast<PolygonizeEdge*>(e_);
cutLines.push_back(e->getLine());
}
}
}